i think i just found a deal though i am not really sure. vsonic gr07 mkii classic color version $86.45
http://www.aliexpress.com/item/VSONIC-GR07-BASS-MKII-Edition-High-Fidelity-Professional-Stereo-Inner-Ear-Earphones-Earbuds/1662004331.html

i never thought about socket difference. i was thinking that they should be the same. about ad826, do they sound like the dual version of ad825? there was a thread on the forum, somebody reviewed alot of opamps suggesting ad8066 and ad825. and thank you for your insightful reply. i owe you one :)

i am gonna use it with superlux hd668b, it is around 50 ohms, i suppose it wouldn't hurt to build it with 2 batteries. i am wondering if there are any other opamps which can perform better, like ad826 or ad8066. anybody have any idea? by the way, thank you all, for all your insightful comments.

i am thinking about building a cmoy. i wandered around the internet and read bunch of stuff.
seems that there was a guy, nwavguy, who did an awesome home amplifier called objective 2 (which is currently sold on jds labs web page, i am sure most of you aware of), which is a nice objective by the way. he also did some measurements on a standart cmoy with a flawed design.
i know there are lots of better desings, but they are too complicated to build (it would be...